Military vehicles used in combat zones must provide ballistic and blast protection for occupants of the vehicle's crew compartment. One of the challenges in designing a military vehicle is to achieve the proper balance between crew protection (survivability) and mobility.
Good mobility generally calls for a vehicle to be lightweight and to have a relatively low center-of-gravity. To achieve a low center-of-gravity, the vehicle should sit as low to the ground as possible while still providing required ground clearance.
Survivability, on the other hand, drives vehicle design towards more armor, resulting in more weight and therefore a higher center-of-gravity. One way to improve survivability versus a detonation originating close to or below the crew compartment (such as detonation of a lane mine or IED) is to increase the clearance between the bottom of the crew compartment and ground. Increased armor weight and greater ground clearance may result in the vehicle center-of-gravity being so high as to cause an unacceptable roll-over risk when travelling over uneven terrain.
Improved vehicle survivability has recently been demonstrated by what is referred to as a Double-V hull configuration, the general concept of which is shown in FIGS. 1a and 1b. In the Double-V configuration, sloping or angled outward-facing surfaces extending along both sides of the lower portion of the vehicle hull form the first “V” (when viewed from the front or rear of the vehicle, FIG. 1a). The second “V” (when viewed in transverse cross-section, FIG. 1b) is formed by upward-sloping surfaces between the two outboard portions of the hull (sometimes referred to as “pontoons”) and extending to the front and rear along the approximated longitudinal centerline of the vehicle. The sloped lateral surfaces of the first “V” direct detonation energy outward and away from the vehicle if an explosion occurs close to the side of the vehicle. The second, central “V” deals with detonations originating directly beneath the vehicle, between the pontoons, by directing the energy of the detonation forward and/or rearward to reduce the amount of kinetic energy transferred to the hull and its occupants.